It's Time for the prom: that one special night, usually in May, when girls in colorful gowns and boys in ill-fitting tuxedos pose awkwardly for photos that they will cherish (or rue) for the rest of their lives. The night when curfews are broken and limousines are taken for joyrides. The night when the punch bowl might contain more than just punch.

The word prom is short for promenade, the formal, introductory parading of guests at a party. The prom can be traced back to the simple co-ed banquets that 19th century American universities held for each year's graduating class. A growing teenage culture pushed proms younger and younger, and by the 1940s the adolescent dance we know today had almost entirely taken hold. In the 1950s, a thriving postwar economy allowed high schools to eschew the traditional gymnasium in favor of proms held in hotels or at country clubs. President Kennedy rescheduled a 1963 $1,000-a-plate fundraiser at the Beverly Hilton to accommodate a local school whose prom had been booked for the same time. In 1975, President Ford's daughter Susan held her high school's senior prom at possibly the best prom location ever: the White House.

As cultural mores have changed, so has the prom--begrudgingly. An Alabama principal was sued in 1994 for threatening to cancel the prom if interracial couples attended. And despite the two South Dakota boys who in 1979 became one of the first known same-sex couples to openly attend a prom, some schools still have anti-gay bans in place. In April, a Mississippi school district canceled its prom rather than allow a student to bring her girlfriend as her date. And while going stag was once social suicide, some kids now attend in groups rather than as couples. But don't worry: between choosing the right outfit and attending the right after-party, there's still more than enough anxiety to go around.